Depends on what sound you want. Ive seen some guys pretty much run the same set up you have and love it... Others prefer the Borla or mangnaflow. You may wanna check YouTube and just see what you like.

I had alot of problems blowing my mufflers off until i used a high impact. I have LT's and o/r x with custom fiberglass mufflers and its crazy loud. Inside there isn't much sound other than that from the headers but mine sounds like its from hell. Some like it and some dont. But driving normal it has a semi deep mellow tone but if you get on it, it wakes the dead. I had flowmasters but i hated the interior noise so had to change it...just my view tho